Vacuum pump and vacuum system including the same

ABSTRACT

A vacuum pump and a vacuum system can be stopped when necessary when an engine is operating.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2006-0037540 filed in the Korean Intellectual Property Office on Apr. 26, 2006, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a vacuum pump that can stop when necessary when an engine operates.

(b) Description of the Related Art

Generally, a vehicle utilizes vacuum pressure as operating power for a number of components, for example, a brake, an exhaust-gas recirculation (EGR) valve, and a turbo charger actuator. In order to generate the vacuum pressure, a vacuum pump is utilized.

A vane type vacuum pump including a vane, a rotor, a drive shaft, a base housing, and an outer housing has been typically utilized as the vacuum pump. The vane type vacuum pump includes the outer housing forming a cylindrical space therein and the rotor connected to the vane rotates in the cylindrical space.

Therefore, if the vacuum pump starts operating with an engine, the vane in the vacuum pump rotates along a round shape track mechanically formed to the base housing. A volume change occurs by the vane rotation and the volume change generates a vacuum pump power. The vacuum pump is connected to a cam shaft or an alternator operated by a belt and is always operated when the engine operates.

In the process where vacuum pump power is generated by the vacuum pump operating, a very high frictional force occurs. The frictional force of the vacuum pump constitutes a large portion of a mechanical frictional force occurring in a vehicle.

More particularly, while the engine operates, because the EGR valve, the turbo charger actuator, the brake, etc., are only utilized intermittently, a problem occurs that engine fuel consumption is increased needlessly.

That is, according to the vacuum pump of the prior art, problems occur that unnecessary output consumption is excessive, and startability and emission (EM) characteristics are deteriorated.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a vacuum pump and a vacuum system having advantages of reducing a frictional force of the vacuum pump and enhancing engine efficiency by cutting off transmission of a driving torque of the vacuum pump to a vane of the vacuum pump in a case that a predetermined vacuum pressure is formed in a vacuum tank.

An exemplary embodiment of the present invention provides a vacuum pump supplying vacuum pressure including a pump main body generating the vacuum pressure and a power transmitting portion transmitting a power to the pump main body, wherein the power transmitting portion includes: a case forming a receiving part therein and forming a first gear in an interior circumference; a ring assembly located in the case such that the ring assembly selectively transmits the power to the first gear, the ring assembly including a ring shaped outer-geared ring forming a second gear at an exterior circumference of the outer-geared ring to be geared to the first gear and a ring shaped inner-geared ring forming a third gear at an inner circumference of the inner-geared ring; a gear shaft including a fourth gear formed to transmit the power to the third gear and located penetrating the ring assembly; and a supporting member located between one side of the case and one side of the ring assembly to support the ring assembly.

An oil supplying hole is formed to the case such that fluid can inflow between the ring assembly and the case, which confront each other.

The ring assembly may include at least a pair of outer-geared rings located at both ends of the receiving part and an inner-geared ring between the outer-geared rings.

The inner-geared ring may be realized as a plurality with outer-geared rings located between the plurality of inner-geared rings.

Alternatively, the ring assembly may include at least a pair of inner-geared rings located at both ends of the receiving part and an outer-geared ring located between the inner-geared rings.

The outer-geared ring may be realized as a plurality with inner-geared rings located between the plurality of outer-geared rings.

Another embodiment of the present invention provides a vacuum system generating and supplying a vacuum pressure including a vacuum tank storing the vacuum pressure, an oil pump supplying an oil to generate the vacuum pressure, a vacuum pump operating to make the vacuum tank to be in a vacuum state, a solenoid valve located on a hydraulic line between the vacuum pump and the oil pump such that fluid is selectively supplied to the vacuum pump, and an electronic control unit (ECU) controlling the solenoid valve on the basis of information of a vacuum state of the vacuum tank, wherein the vacuum pump supplying the vacuum pressure includes a pump main body generating the vacuum pressure and a power transmitting portion transmitting a power to the pump main body, wherein the power transmitting portion includes: a case forming a receiving part therein, forming a first gear at an interior circumference, and including an oil supplying hole formed such that the fluid inflows into the case; a ring assembly located in the case such that the ring assembly selectively transmits the power to the first gear, the ring assembly including a ring shaped outer-geared ring forming a second gear at an exterior circumference of the outer-geared ring to be geared to the first gear and a ring shaped inner-geared ring forming a third gear at an inner circumference of the inner-geared ring; a gear shaft including a fourth gear formed to transmit the power to the third gear and located penetrating the ring assembly; and a supporting member located between one side of the case and one side of the ring assembly to support the ring assembly.

The ring assembly may include at least a pair of outer-geared rings located at both ends of the receiving part and an inner-geared ring between the outer-geared rings.

The inner-geared ring may be realized as a plurality with outer-geared rings located between the plurality of inner-geared rings.

Alternatively, the ring assembly may include at least a pair of inner-geared rings located at both ends of the receiving part and an outer-geared ring located between the inner-geared rings.

The outer-geared ring may be realized as a plurality with inner-geared rings located between the plurality of outer-geared rings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vacuum pump according to an exemplary embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a power transmitting portion of a vacuum pump according to an exemplary embodiment of the present invention.

FIG. 3A is a front view showing an outer-geared ring according to an exemplary embodiment of the present invention.

FIG. 3B is a front view showing an inner-geared ring according to an exemplary embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a power transmitting portion of a vacuum pump according to an exemplary embodiment of the present invention.

FIG. 5 is a schematic diagram of a vacuum system according to an exemplary embodiment of the present invention.

FIG. 6 is a flowchart showing an operating process of a vacuum system according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments of the present invention will hereinafter be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, according to an exemplary embodiment of the present invention, a vacuum pump 10 includes a pump main body 200 and a power transmitting portion 100. Pump main body 200 is a general pump main body wherein a vane (not shown) located therein rotates to form a vacuum. In addition, a power transmitting portion 100 is formed to transmit a power only when necessary and to not transmit the power when not necessary according to the exemplary embodiment of the present invention.

The pump main body 200 forms a vacuum pressure and the power transmitting portion 100 transmits a power to the pump main body 200. That is, the power transmitting portion 100 receives a power from an engine and transmits the power to the pump main body 200.

Referring to FIG. 2, according to an exemplary embodiment of the present invention, the power transmitting portion 100 includes a cylindrical case 110, a supporting member 140, a ring assembly 120, a ring shaped cover 150, and a gear shaft 130.

The supporting member 140 may be realized as a spring.

A detailed description of each constituent element of the power transmitting portion 100 is described hereinafter.

Case 110 forms a receiving part 111 and is formed as a cylindrical shape. In addition, a first gear 110 a is formed at an interior circumference of the case 110. A supporting member mounting portion 112 is formed to one side of the receiving part 111 such that a position of the supporting member 140 can be secured. An oil supplying hole 113 is formed to the supporting member mounting portion 112 such that fluid can inflow from outside.

Bolt holes 114 to connect the cover 150, described later, are formed to an edge of an open portion of the case 110. A ring shaped ring assembly 120 is mounted in the case 110 and the supporting member 140 is located between the ring assembly 120 and the supporting member mounting portion 112. Therefore, one end of the supporting member 140 is contacted to the supporting member mounting portion 112 formed to one side of the receiving part 111 and the other end of the supporting member 140 is contacted to one side of the ring assembly 120. That is, the supporting member 140 is located to support the ring assembly 120.

A detailed description of the ring assembly 120 is described hereinafter.

The ring assembly 120 includes a ring shaped outer-geared ring 121 and a ring shaped inner-geared ring 122. In FIG. 2, three outer-geared rings 121 are shown with two inner-geared rings 122 located therebetween.

As shown in FIG. 3A, the outer-geared ring 121 is formed as a ring shape such that an empty space is formed at a center thereof. A second gear 121 a is formed at an exterior circumference of the outer-geared ring 121. The second gear 121 a is formed to be engaged with the first gear 110 a. Therefore, if the outer-geared ring 121 is secured in the case 110, the outer-geared ring 121 and the case 110 are splined with each other through the first gear 110 a and the second gear 121 a.

As shown in FIG. 3B, the inner-geared ring 122 is formed as a ring shape such that an empty space is formed at a center thereof and a third gear 122 a is formed at an interior circumference of the center of the inner-geared ring 122. The third gear 122 a is formed to be engaged to a fourth gear 130 a formed at an exterior circumference of the gear shaft 130, described hereafter. That is, the fourth gear 130 a of the gear shaft 130 is formed to transmit the power to the third gear 122 a.

Therefore, if the gear shaft 130 is inserted to the empty space at the center of the inner-geared ring 122, the third gear 122 a and the fourth gear 130 a are engaged with each other. That is, the inner-geared ring 122 and the gear shaft 130 make a kind of splined connection with each other. In this case, the outer-geared ring 121 does not mean a ring that is located outside of the ring assembly 120 but rather a ring on which gears are formed at an exterior circumference thereof.

In addition, the inner-geared ring 122 does not mean a ring that is located inside of the ring assembly 120 but rather a ring on which gears are formed at an interior circumference thereof. Therefore, although the outer-geared rings 121 are located at both ends of the ring assembly 120 and the inner-geared rings 122 are located therebetween in FIG. 2, the inner-geared rings 122 may be located at both ends with the outer-geared rings 121 located in between. That is, an arrangement of the inner-geared rings 122 and the outer-geared rings 121 can be changed according to a required friction amount.

For example, a pair of inner-geared rings 122 may be disposed between the supporting member 140 and the cover 150 and an outer-geared ring 121 may be disposed between the pair of inner-geared rings 122.

In a case that a hydraulic pressure is applied in the case 110, the outer-geared rings 121 and the inner-geared rings 122 are contacted with each other and rotate together. That is, the ring assembly 120 selectively transmits the power to the first gear 110 a, that is, to the case 110. In addition, contacting surfaces of the inner-geared rings 122 and the outer-geared rings 121 may have a large friction coefficient.

As shown in FIG. 2, according to an exemplary embodiment of the present invention, both surfaces of each inner-geared ring 122 have a large friction coefficient such that the frictional force acting on the contacting surfaces between the three outer-geared rings 121 and the two inner-geared rings 122 becomes high.

The cover 150 is located outside of the ring assembly 120. The cover 150 is formed as a ring shape such that a center portion thereof has an empty space and penetration holes 151, to be connected with bolts 152, are formed to an edge of the cover 150.

FIG. 4 shows a state where hydraulic pressure is applied to the power transmitting portion so that the outer-geared rings 121 and the inner-geared rings 122 are contacted with each other.

Referring to FIG. 5 and FIG. 6, a detailed description of an operating process of the vacuum pump will now be described.

According to an exemplary embodiment of the present invention, the vacuum system generating and supplying a vacuum pressure includes a vacuum tank 60, an oil pump 30, a vacuum pump 10, a solenoid valve 40, and an electronic control unit (ECU) 50.

ECU 50 may comprise a processor, memory, and associated hardware and software as maybe selected and programmed by persons of ordinary skill in the art based on the teachings of the present invention as contained herein.

The vacuum tank 60 stores the vacuum pressure and the oil pump 30 supplies oil for generating the vacuum pressure. The vacuum pump 10 operates to create a vacuum inside the vacuum tank 60 and the solenoid valve 40 is located on a hydraulic line between the vacuum pump 10 and the oil pump 30 to selectively supply the fluid to the vacuum pump 10.

The vacuum pressure stored in the vacuum tank 60 is utilized to operate an exhaust gas recirculation (EGR) valve, a turbo charger actuator, and a brake, and the ECU 50 controls the solenoid valve 40 on the basis of information related to a vacuum state of the vacuum tank 60. The vacuum pump 10 includes the pump main body 200 and the power transmitting portion 100 and because a detailed description of the vacuum pump 10 is described above, the description related thereto is omitted here.

A vacuum pump gear 21 is engaged to one side of the gear shaft 130 of the vacuum pump 10 and a crank gear 22 is engaged to the vacuum pump gear 21. The crank gear 22 is connected to an engine 23 and rotates by an operation of the engine 23.

The vacuum pump 10 is connected to the oil pump 30 through a hydraulic line supplying oil from the oil pump 30. The solenoid valve 40 is located on the hydraulic line between the oil pump 30 and the vacuum pump 10 to open and close the hydraulic line. As described above, the solenoid valve 40 is controlled by the ECU 50.

The vacuum tank 60 is connected to the EGR valve, the turbo charger actuator, and the brake to supply the vacuum pressure to the EGR valve, the turbo charger actuator, and the brake. Therefore, if the engine 23 starts, the crank gear 22 rotates, and if the crank gear 22 rotates, the vacuum pump gear 21 rotates. Gear shaft 130 rotates and as described, the inner-geared ring 122 rotates by the fourth gear 130 a and the third gear 122 a.

In a case where the outer-geared ring 121 and the inner-geared ring 122 are apart from each other, because a rotation of the inner-geared ring 122 does not affect the outer-geared ring 121, only the inner-geared ring 122 freely rotates. That is, in the case that the outer-geared ring 121 and the inner-geared ring 122 are apart from each other, power delivery from the inner-geared ring 122 to other constituent elements is not generated.

However, in a case where the outer-geared ring 121 and the inner-geared ring 122 are contacted with each other, if the inner-geared ring 122 rotates, the case 110 rotates together through the second gear 121 a and the first gear 110 a. That is, if the case 110 rotates, the vacuum pump 10 operates, by which the vane (not shown) of the pump main body 200 rotates.

If the engine 23 starts, the inner-geared ring 122 always rotates by sequential transmission of an engine torque through the crank gear 22, the vacuum pump gear 21, and the gear shaft 130. However, the outer-geared ring 121 does not always rotate, but only rotates when acted on by a frictional force of the inner-geared ring 122. In addition, the vacuum pump operates only in a case that the outer-geared ring 121 rotates, and thereby the vane (not shown) in the pump main body 200 rotates.

The detailed operating process of the vacuum pump is described hereinafter referring to FIG. 6. First, the ECU 50 detects pressure of the vacuum tank 60 at step S110.

That is, information related to the detected pressure of the vacuum tank 60 is transmitted to the ECU 50.

If, according to the detected result, a vacuum is not formed, the ECU 50 opens the solenoid valve 40 located on the hydraulic line connecting the oil pump 30 with the oil supplying hole 113 of the vacuum pump 10 at step S141.

If the solenoid valve 40 opens, oil in the oil pump 30 inflows into the case 110 of the vacuum pump 10 through the oil supplying hole 113 at step S142.

If the oil inflows into the case 110, hydraulic pressure is applied to the outer-geared ring 121 at step S143.

That is, as shown in FIG. 4, the oil pushes the outer-geared ring 121.

If the hydraulic pressure is applied to the outer-geared ring 121, as shown in FIG. 4, the outer-geared ring 121 and the inner-geared ring 122 are engaged at step S144.

If the outer-geared ring 121 and the inner-geared ring 122 are engaged with each other by friction, the torque of the inner-geared ring 122, which is always rotating, rotates the case 110 through the outer-geared ring 121 at step S145.

If the case 110 rotates, the vane (not shown) rotates and the vacuum pump 10 operates at step S146.

That is, the vacuum pump 10 is operated by the torque of the gear shaft 130 rotating the case 110.

A case where the pump main body 200 stops is described hereinafter.

First, the ECU 50 detects the pressure of the vacuum tank 60 at step S110.

That is, information related to the detected pressure of the vacuum tank 60 is transmitted to the ECU 50.

If, according to the detected result, a vacuum is not necessary, the ECU 50 closes the solenoid valve 40 at step S131.

If the solenoid valve 40 closes, the application of the hydraulic pressure from the vacuum pump 10 to the power transmitting portion 100 is released at step S132.

If the hydraulic pressure is not applied to the vacuum pump 10, the hydraulic pressure does not act on the outer-geared ring 121 and the engagement of the outer-geared ring 121 and the inner-geared ring 122 is released at step S133.

If the engagement between the outer-geared ring 121 and the inner-geared ring 122 is released, the torque of the gear shaft 130 and the outer-geared ring 121 is not transmitted to the inner-geared ring 122 and the case 110 at step S134.

If the case 110 does not rotate, because the power delivery to the pump main body 200 is cut off, the rotation of the vane located in the pump main body 200 is also ceased and the operation of the vacuum pump 10 stops at step S135.

According to embodiments of the present invention, because the vacuum pump selectively operates when necessary, durability of the vacuum pump improves and because unnecessary power loss is prevented, engine efficiency is enhanced.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 

1. A vacuum pump for supplying vacuum pressure, comprising a pump main body configured for generating the vacuum pressure therein, and a power transmitting portion transmitting a power to the pump main body, wherein the power transmitting portion comprises: a case forming a receiving part therein and forming a first gear in an interior circumference; a ring assembly located in the case such that the ring assembly selectively transmits the power to the first gear, the ring assembly including a ring shaped outer-geared ring forming a second gear at an exterior circumference of the outer-geared ring to be geared to the first gear and a ring shaped inner-geared ring forming a third gear at an inner circumference of the inner-geared ring; a gear shaft comprising a fourth gear formed to transmit the power to the third gear and located penetrating the ring assembly; and a supporting member located between one side of the case and one side of the ring assembly to support the ring assembly.
 2. The pump of claim 1, wherein an oil supplying hole is formed in the case such that fluid can inflow between the ring assembly and the case, which confront each other.
 3. The pump of claim 2, wherein the ring assembly comprises: at least a pair of outer-geared rings located at both ends of the mounting portion; and an inner-geared ring between the outer-geared rings.
 4. The pump of claim 3, wherein: the inner-geared ring comprises a plurality of rings; and outer-geared rings are located between the plurality of inner-geared rings.
 5. The pump of claim 2, wherein the ring assembly comprises: at least a pair of inner-geared rings located at both ends of the mounting portion; and an outer-geared ring located between the inner-geared rings.
 6. The pump of claim 5, wherein: the outer-geared ring comprises a plurality of rings; and inner-geared rings are located between the plurality of outer-geared rings.
 7. A vacuum system generating and supplying a vacuum pressure, comprising: a vacuum tank storing the vacuum pressure; an oil pump supplying an oil to generate the vacuum pressure; a vacuum pump operating to make the vacuum tank to be in a vacuum state; a solenoid valve located on a hydraulic line between the vacuum pump and the oil pump such that fluid is selectively supplied to the vacuum pump; and an electronic control unit (ECU) controlling the solenoid valve on the basis of information of a vacuum state of the vacuum tank, wherein the vacuum pump supplying the vacuum pressure comprises: a pump main body generating the vacuum pressure; and a power transmitting portion transmitting a power to the pump main body, wherein the power transmitting portion comprises: a case forming a receiving part therein, forming a first gear at an interior circumference, and comprising an oil supplying hole formed such that the fluid inflows into the case; a ring assembly located in the case such that the ring assembly selectively transmits the power to the first gear, the ring assembly comprising a ring shaped outer-geared ring forming a second gear at an exterior circumference of the outer-geared ring to be geared to the first gear and a ring shaped inner-geared ring forming a third gear at an inner circumference of the inner-geared ring; a gear shaft comprising a fourth gear formed to transmit the power to the third gear and located penetrating the ring assembly; and a supporting member located between one side of the case and one side of the ring assembly to support the ring assembly.
 8. The system of claim 7, wherein the ring assembly comprises: at least a pair of outer-geared rings located at both ends of the mounting portion; and an inner-geared ring between the outer-geared rings.
 9. The system of claim 8, wherein: the inner-geared ring comprises a plurality of rings; and outer-geared rings are located between the plurality of inner-geared rings.
 10. The system of claim 7, wherein the ring assembly comprises: at least a pair of inner-geared rings located at both ends of the mounting portion; and an outer-geared ring located between the inner-geared rings.
 11. The system of claim 10, wherein: the outer-geared ring comprises a plurality of rings; and inner-geared rings are located between the plurality of outer-geared rings. 